Pipe-threading machine



Nov. 4 1924.

- B. BORDEN PIPE THREADING MACHINE Filed July 1, 192] invent or;

Atty

Patented Nov. 4, 1924.

urrs BRADFORD BORDEN, OF TORONTO, ONTARIO, CANADA.

PIPE-THREADING BIACHINE.

Application filed July 1,

To all whom it may concern:

Be it known that I, BRADFORD BORDEN, a citizen of the United States of America, and resident of 110 Church St, in the city of Toronto, in the 'county of York, in the Province of Ontario, in the Dominion of Canada, have invented certain new and useful Improvements in Pipe-Threading Machines, of which the following is a specification.

The invention relates to improvements in pipe threadin machines as described in the present speci cation and illustrated in the accompanying drawings that form a part of the same. i

The invention consists essentially of the novel construction and arrangement of parts whereby during the threading operation the dies are caused to recede and at the end of the out are automatically freed from engagement with the pipe.

The objects of the invention are to eliminate the use of a leader screw and the consequent necessity of having to turn the machine backover the thread in order to disengage same, to .provide a machine in which the dies are readily interchangeable, to economize in time and labor in threading pipes and generally to provide a pipe threading machine which will be inexpensive to manufacture, durable and efiicient.

' In the drawings, Figure 1 is a plan viewof the device.

Figure 2 is a side elevation.

Figure 3 is a vertical sectional view taken on line 33 of Figure 2.

Figure 4: is a plan view of the support for the posts.

Like numerals of reference indicate corresponding parts in the various figures.

Referring to the drawings the main support for the various parts consists of a substantially square plate or yoke 1 having its centre cut away forming a circular opening 2.

Each of the corners of the plate 1 is provided with an opening 3 therethrough into which is adapted to be secured a post 4, said posts forming a means for adjustably supporting the die holding member and being locked to their positions by means of set screws 4* threading through the frame 1 and bearing against said posts.

The outer portion of each of the posts 4 is circular for the greater portion of its circumference but has a flat inner face 5 tapering downwardly and inwardly at a 1921. Seria11 To.481,850.

incline adapted to correspond to the taper of thread required to a point 6 slightly above its longitudinal centre from which point it inclines inwardly sharply a short distance and then extends downwardly a short distance at an inward taper forming a slot 7 terminating in 'a right angular cut extending inwardly from the circular lower part 8 of said posts, said out forming a shoulder 9 adapted to provide a stop for the dies as will be explained hereinafter.

The die holding device consists of a sub-. stantially square frame 10 having circular openings through the corners thereof adapted to loosely encircle the posts 4 respectively so as to permit of said frame sliding freely thereon and having its centre cut away forming a circular pipe opening 11, said die holder being held to its position on said posts by means of pins 1O extending therethrough and sliding in grooves 10 in the rear sides of said posts respectively.

The frame 10 is provided at each of'its corners with a thickened portion or boss 12 extending inwardly to the edge of the pipeopening 11 and being'slotted longitudinally as at 13 forming a slideway in which a die 14L is adapted to operate, the end 15 of said die being adapted to abut the fiat face 5 of the corresponding post.

The frame 10 is preferably formed with a pair of sockets 16 projecting from opposite sides thereof to permit of securing handles 17 thereto for rotating the device.

. V In order to insure a proper centering of the pipe in relation to the dies 14 during the thread cutting operation an appropriate gripping device 19 is employed as shown in Figures 2 and 3, the same having a reduced portion adapted to project through the opening 11 in the post supporting plate 1, the upper end of which reduced .portion terminates in a threaded neck 20. As shown in Figure 3 the plate 1 is rotatably supported by the circumferential shoulder 19 ad jacent said reduced portion, the threaded neck 20 receiving a screw collar 21 whereby a rotatable attachment is eifected between said gripping device and plate.

The gripping device illustrated herein is of well known form, the same including radially slidable pipe engaging jaws 26 actuated toward and from the axis of the opening 11 by means of a cam connection with a rotatable ring-like plate controlled by a handle 27. However, since the gripping device, per se, forms no part of the present invention further description thereof is deemed unnecessary.

The form of die which it is considered preferable to use is one consisting of two sets of teeth 23 and 24: spaced by a slot 25, the set 23 which is the first set to come into contact with the pipe being set inwardly slightly in relation to the set 24- so that in operation the pipe will be properly gripped and a thread roughed out preparatory to being properly out by the projecting set 24.

In the operation of this invention the device is placed over the pipe with the end to. be cut abutting the dies after which the jaws 26 of the centering devic are closed over the pipe by means of the handle 27. The device is then rotated by means of the handles 17 gradually cutting a thread of desired size. its the dies are drawn on to the pipe by theinwardly winding thread the ends abutting the posts are forced along the fiat tapered faces 5 thereof thus causing said dies to recede from the pipe a ratio corresponding to the pitch of the taper and when the dies have reached the point 6, the length of said tapered portion being such as to give the required length of thread, they are suddenly projected into the slot 7 forcing them free of engagement with the pipe and terminating the thread so that the device can then be readily withdrawn from the pipe without having to turn the tool back over the thread.

It should be noted that the angular arrangement of the sets of teeth 23 and 24- with the receding tendency of the dies due to contact with the work and the tapered face greatly facilitates the threading operation especially the starting thereof.

What I claim is 1. The combination in a pipe threading machine, of a work holder, a frame rotatably mounted on said work holder, posts extending from said frame parallel with the axis of the work and having inwardly tapered faces terminating in die receiving recesses, a die stock carried by said posts and adapted for sliding movement thereon, toothed dies carried by said die stock being radially movable to engage the work, and the teeth of said dies engaging with the work during rotation of said frame for moving the same in the direction of said support, the pitch of said die teeth causing the dies to recede from the work and lodge in said recesses when the same are reached.

2. The combination, in a pipe threading machine, of a work holder, a frame rotatably mounted on said work holder, posts carried by said frame having inclined surfaces, a die stock having a bore, dies carried by said die stock recedeable from said bore, the extremities thereof adjacent said bore bearing upon the inclined surfaces of said posts which serve to sustain and permit said dies to gradually recede during the threading operation to provide the required pitch for the thread and permit said dies to recede and disengage from the previously cut thread upon completion of the threading operation, so that the machine may be withdrawn off the pipe without rotating it in a reversed direction.

3. The combination in a pipe threading machine, of a work holder, a frame rotatably mounted on said work holder, a die stock having a bore, dies carried by said die stock recedeable from said bore, the extremities thereof adjacent said bore bearing upon inclined surfaces carried by said frame, which serve to sustain said dies and permit the Same to gradually recede during threading operation,to provide the required pitch for the thread, said inclined surfaces terminating in recesses which allow said dies to recede and disengage from the previously cut thread upon completion of the threading operation so that the machine may be withdrawn off the pipe without rotating it in a reversed direction.

4. The combination in a pipe threading machine, of a Work holder, a frame rotatably mounted on said work holder, posts carried by said frame having inclined surfaces terminating in recesses, a die stock having a bore, dies carried by said die stock recedeable from said bore, the extremities thereof adjacent said bore bearing upon the inclined surfaces of said posts which serve to sustain saiddies and permit said dies to gradually recede during the threading operation to provide the required pitch for the thread, said recesses in said postsipermitting said dies to recede and disengage from the previously cut thread upon completion .of the threading operation, so that the machine may be withdrawn ofi the pipe without rotating it in a reversed direction.

5. The combination, in a pipe threading machine, of a work holder, a frame rotatably mounted on said work holder, posts carried by said frame having inclined surfaces, a die stock having a bore, dies carried by said die stock recedeable radially from said bore, the extremities thereof adjacent said bore bearing upon the inclined surfaces of said posts which serve to sustain and permit said dies to gradually recede during the threading operation to provide the required pitch for the thread and permit said diesto recede and disengage from the previously cut thread upon completion of the threading operation, so that the machine may be withdrawn off the pipe without rotating it in the reversed direction.

6. The combination, in a pipe threading machine, of a work holder, a frame rotatably mounted on said work holder, posts carried by said frame having inclined surfaces,

a die stock having a bore, post holes in said die stock, slots registering with said holes, dies inserted in said slots, the extremities thereof adjacent said bore bearing upon the inclined surfaces of said posts which serve to sustain and permit said dies to gradually recede during threading operation to provide the required pitch for the thread and permit said dies to recede and disengage from the previously cut thread upon completion of the threading operation, so that the machine may be withdrawn off the pipe without rotating it in a reversed direction.

7. The combination in a pipe threading machine, of a work holder, a frame rotata bly mounted on said work holder, posts car ried by said frame having inclined surfaces terminating in recesses, a die stock having a bore, post holes in said die stock, die slots registering with said holes, dies disposed in said slots, the extremities thereof adjacent said bore bearing upon the inclined surface of said posts which serve to sustain and permit said dies to gradually recede during the threading operation to provide the required pitch for the thread, said dies upon completion of the threading operation adapted to recede into said recesses and disengage from the previously cut thread, so that the machine may be Withdrawn oil the pipe without rotating it in the reversed direction.

8. In a pipe threading machine, the combination of a rotatable support, posts carried transversely of said support and having inclined faces, a die stock slidably carried by said posts and having a work receiving opening therein, bosses formed upon said die stock radially disposed with respect to' said work receiving opening and having longitudinal die receiving slots therein in communication with said posts, dies carried in said slots and movable to and from engagement with the work, angularly disposed sets of teeth formed upon the work engaging ends of said dies and being inclined away from said Work, the other ends of said dies being beveled to correspond to the angle of the inclined faces of said posts, said sets of die teeth progressively biting into the Work upon rotation of said support for moving the die stock in the direction thereof, and the angular formation of said sets of teeth urging the beveled ends of said dies against the inclined faces of said posts for gradually receding the same from the work and forming a tapered thread thereon.

Signed at the city of Toronto, this 20th day of June, 1921.

BRADFORD BORDEN.

Witnesses G. MURPHY, F. U. BROMLEY. 

